1. Field of the Invention
The present invention relates generally to improvements in systems for reading bar codes, and particularly to advantageous aspects of a system and methods for the detection and correction of errors in the reading of bar codes.
2. Description of the Prior Art
Bar coding systems, such as the Uniform Product Code (UPC) system, are commonly used to identify items, such as products for sale in a retail store. In such systems, bar codes consisting of a series of bars and spaces of varying widths are printed onto labels that are affixed to the products for sale, or are printed directly onto the product packaging. Scanners at the checkout terminal are then used to read the bar codes. This approach allows more information to be entered in less time, as scanning requires significantly less time than manually entering pricing and product identification information. Further, the use of bar codes eliminates errors arising from keyboarding errors by checkout personnel.
Unfortunately, bar-coded labels are not always printed perfectly. Imperfections caused by the printing process frequently render the printed bar code unreadable to the bar code scanning equipment. Such cases require human intervention. Typically, the method of human intervention is to enter the bar code data manually into a keyboard, terminal, or other input device. The prevalence of this problem is one reason that the data on most bar-coded labels are printed in human-readable form adjacent to the bars and spaces comprising the bar code itself.
Each human intervention produces a delay in the scanning process. There is thus a need for a scanning system that minimizes the number of human interventions required.